RegExr vs The Regex Coach

RegExr is a free web tool for learning, building, and testing regular expressions. It supports JavaScript and PHP/PCRE expressions, with results that change as you type. Hovering over a match or expression reveals details, and the Explain tool describes an expression in plain English. Tests mode lets users assemble examples that an expression should match or reject. Replace and List produce custom outputs, while Details shows capture groups. Learning resources include a cheatsheet, reference, help pages, and examples. Users can search and rate Community Patterns, then save and share expressions. Signing in keeps favorites and patterns in My Patterns. A saved expression gets a public link, and a Community-shared copy cannot be edited or deleted. The listed RegExr plan costs nothing. The project README credits Grant Skinner and gskinner.com as creators and identifies this version as GPL v3 licensed. It directs issue and feature requests to GitHub and regular-expression questions to Stack Overflow.

The Regex Coach is a graphical application for experimenting interactively with Perl-compatible regular expressions. It shows whether a pattern matches a target string and updates the interface when changes are made. Users can highlight captured groups or selected parts of a pattern in the target text. The application can attempt a plain-English explanation of a regex, show its parse tree graphically, and step through the matching process. It also simulates Perl split and substitution operations. Written in Common Lisp, it uses CL-PPCRE as its regex engine. The current Windows download is version 0.9.2; the maker says the program has not changed since 2008. Linux is no longer maintained, though an unsupported 0.8.5 release is available and also runs on FreeBSD. There is no Mac version planned. The program is provided as-is without warranty, and the maker says not to expect support for older Windows configurations or the unsupported Linux release. The engine may overflow its stack with relatively long regular expressions. The listed plan is free, with conditions for commercial use and redistribution.